In the IP Multimedia Subsystem (IMS) architecture, the Ro interface is used to connect network elements to online charging systems (OCS). The 3rd Generation Partnership Project (3GPP) standards body for GSM networks has extended this and defined both CAP and Ro as the interfaces into the OCS. The 3rd Generation Partnership Project 2 (3GPP2) standards body for CDMA networks has defined Ro as the interface not providing a solution for its IN networks. Today, many OCS systems support the Ro interface and do not support the CAP interface. To close this gap Online Mediation solutions are used to mediate between Ro and CAP, Ro and WIN2.
Today, there is no standard approach to implement this mediation, and, thus, solutions tend to be limited and are not cohesive and consistent across different network interfaces.
Over the last five years, operator and network consolidation has become more common. This consolidation has left many operators in a situation in which they have an OCS which supports Ro and multiple network protocols including Ro, Camel (CAP2, CAP3, CAP4), WIN2, SIP/ISC, etc. The problem of not having a cohesive and consistent mediation solution across all of a particular operator's network interfaces introduces cases in which different subscribers in the same network each receive a different user experience.